1. Field of the Invention
The present invention relates to surgically inserted intraocular lenses, and more particularly to the apparatus and method for inserting liquid filled lenses into the natural capular bag of an eye.
2. Description of the Prior Art
Surgical implantation of synthetic intraocular lenses is a known practice in the treatment of optical diseases and is a method of preference in the treatment of cataract. Most typically the implanted lens is of a hard material (acrylic or silicon polymer) inserted in the ciliary sulcus or within the natural lens capsule of the eye after removal of the anterior capsule and the lens substance. While acceptable in many instances, a hard lens implant occasionally causes irritation.
While widely practiced, both the hard lens and the soft lens implants are large and thus entail extensive surgical incision with consequent extensive trauma. More importantly, lens shape, and position must be selected at the time of surgery and the lens must be securely fixed against movement. All these factors prompted alternative procedures, particularly procedures which permit post operative lens modification with minimal trauma.
One such procedure is described in U.S. Pat. No. 4,373,218 to Schachar. This procedure entails the insertion of an expandable sack into the cavity previously occupied by the lens capsule of the eye. A tube or neck projecting from the sack is then available for adding or withdrawing fluid which thus controls the inserted shape of the sack.
While suitable for the purposes intended this last procedure entails extraction of the natural lens capsule, an event coupled with unavoidable trauma, and the movement of vitreous liquid anterialy. Accordingly, less traumatic corrections of a diseased eye are extensively sought and it is one such technique that is disclosed herein.